At present, traffic LED signal lamps are widely used in traffic such as in roads and railways. Main faults of traffic LED signal control include: short circuit of a bidirectional silicon controlled rectifier, open circuit of a bidirectional silicon controlled rectifier, and vulnerability of high voltage alternating current (AC)/direct current (DC) driver provided within the signal lamp. Breakdown resulted short circuit in the high voltage driving of the bidirectional silicon controlled rectifier in the controller is the main reason for the serious faults like the “green conflict” (that is, the phenomenon that the green light is always on), which is originated from inherent defects of the systematic circuit design and the bidirectional silicon controlled rectifier, and is one of the main reasons for the high failure rate of the current traffic signal controller and the signal lamp.
Moreover, due that for each signal lamp, high damage rate (one of the reasons is the cause of the transient high voltage impulsion at frequent switching) of the built-in AC/DC driving power also leads to high failure rate of the signal lamp, thereby affecting the service life of the LED signal lamp.